I wondered about this too and asked about it on the security stackexchange forum in case I was overlooking some glaringly obvious reason not to. Turns out that

I wondered about this too and asked about it on the security stackexchange forum in case I was overlooking some glaringly obvious reason not to. Turns out that most thought it was reasonable too, though maybe too frustrating for some. https://security.stackexchange.com/q/12828/8518 https://security.stackexchange.com/q/12828/8518